Hesperetin: an inhibitor of the transforming growth factor-β (TGF-β) signaling pathway

Exploring the Potential of Hesperidin in Preventing Hypertrophic Scars: Insights from a Rabbit Ear Model

Background

Hypertrophic scars, commonly occurring after trauma or surgery in critical areas like the head and joints, pose significant challenges to both physical and mental health due to their impact on skin function and aesthetics. While the complex pathogenesis involves fibroblast activation and collagen deposition, effective treatments are lacking, underscoring the importance of exploring pathogenesis and targeted therapies. Hesperidin, a bioactive compound in citrus fruits with diverse health benefits, including anti-fibrotic and anti-angiogenic effects, is the focus of this study with the aim of investigating its impact on hypertrophic scar formation, given its potential to promote blood flow and improve skin microcirculation.

Objective

This study aimed to observe the inhibitory effect of topical hesperidin on hypertrophic scars in rabbits.

Methods

A total of 8 healthy adult New Zealand white rabbits were used to establish a rabbit hypertrophic scarring animal model. Five wounds were created on each rabbit's two ears, with three wounds on the left ear (groups A, B, and C) and two wounds on the right ear (groups D and E). After six days of wound drying postoperatively, the wounds were locally treated with medication as followed: group A, 0.1% hesperidin; group B, 1% hesperidin; group C, 1% triamcinolone acetonide; group D, Vaseline; and group E, blank control without any medication. After 28 days, the scar tissue samples were collected for histological examination.

Results

The results showed that the scar texture of groups B and C was softer and lighter in color, and the number of fibroblasts, capillaries, and inflammatory cells in the tissue was significantly less than those in the other three groups. The hypertrophic scar indices of groups B and C were significantly smaller than those of groups A, D, and E, and the difference was statistically significant (P < 0.05). There were no significant difference between groups B and C.

Conclusion

Topical application of hesperidin demonstrated promising potential for reducing hypertrophic scar formation in rabbits.

Recent Progress in the Hesperetin Delivery Regimes: Significance of Pleiotropic Actions and Synergistic Anticancer Efficacy

BACKGROUND

In the plant kingdom, flavonoids are widely distributed with multifunctional immunomodulatory actions. Hesperetin (HST) remains one of the well-studied compounds in this domain, initially perceived in citrus plants as an aglycone derivative of hesperidin (HDN).

OBSERVATIONS

Natural origin, low in vivo toxicity, and pleiotropic functional essence are the foremost fascinations for HST use as an anticancer drug. However, low aqueous solubility accompanied with a prompt degradation by intestinal and hepatocellular enzymes impairs HST physiological absorption.

MOTIVATION

Remedies attempted herein comprise the synthesis of derivatives and nanocarrier (NC)-mediated delivery. As the derivative synthesis aggravates the structural complexity, NC-driven HST delivery has emerged as a sustainable approach for its sustained release. Recent interest in HST has been due to its significant anticancer potential, characterized via inhibited cell division (proliferation), new blood vessel formation (angiogenesis), forceful occupation of neighboring cell's space (invasion), migration to erstwhile physiological locations (metastasis) and apoptotic induction. The sensitization of chemotherapeutic drugs (CDs) by HST is driven via stoichiometrically regulated synergistic actions. Purpose and Conclusion: This article sheds light on HST structure-function correlation and pleiotropic anticancer mechanisms, in unaided and NC-administered delivery in singular and with CDs synergy. The discussion could streamline the HST usefulness and long-term anticancer efficacy.

Spectroscopic Characterization and Biological Activity of Hesperetin Schiff Bases and Their Cu(II) Complexes

The three Schiff base ligands, derivatives of hesperetin, HHSB (N-[2,3-dihydro-5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chromen-4-ylidene]isonicotinohydrazide), HIN (N-[2,3-dihydro-5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chromen-4-ylidene]benzhydrazide) and HTSC (N-[2,3-dihydro-5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chromen-4-ylidene]thiosemicarbazide) and their copper complexes, CuHHSB, CuHIN, and CuHTSC were designed, synthesized and analyzed in terms of their spectral characterization and the genotoxic activity. Their structures were established using several methods: elemental analysis, FT-IR, UV-Vis, EPR, and ESI-MS. Spectral data showed that in the acetate complexes the tested Schiff bases act as neutral tridentate ligand coordinating to the copper ion through two oxygen (or oxygen and sulphur) donor atoms and a nitrogen donor atom. EPR measurements indicate that in solution the complexes keep their structures with the ligands remaining bound to copper(II) in a tridentate fashion with (O^-, N, O_ket) or (O^-, N, S) donor set. The genotoxic activity of the compounds was tested against model tumour (HeLa and Caco-2) and normal (LLC-PK1) cell lines. In HeLa cells the genotoxicity for all tested compounds was noticed, for HHSB and CuHHSB was the highest, for HTSC and CuHTSC-the lowest. Generally, Cu complexes displayed lower genotoxicity to HeLa cells than ligands. In the case of Caco-2 cell line HHSB and HTSC induced the strongest breaks to DNA. On the other side, CuHHSB and CuHTSC induced the highest DNA damage against LLC-PK1.

Hesperetin as an anti-SARS-CoV-2 agent can inhibit COVID-19-associated cancer progression by suppressing intracellular signaling pathways

Hesperetin, an aglycone metabolite of hesperidin with high bioavailability, recently gained attention due to its anti-COVID-19 and anti-cancer properties. Multiple studies revealed that cancer patients are prone to experience a severe form of COVID-19 and higher mortality risk. In addition, studies suggested that COVID-19 can potentially lead to cancer progression through multiple mechanisms. This study proposes that hesperetin not only can be used as an anti-COVID-19 agent but also can reduce the risk of multiple cancer progression by suppressing several intracellular signaling pathways in cancer patients with COVID-19. Therefore, in this review, we attempted to provide evidence demonstrating anti-COVID-19/cancer properties of hesperetin with several mechanisms.

Hesperetin regulates transforming growth factor-β1/Smads pathway to suppress epithelial-mesenchymal transition -mediated invasion and migration in cervical cancer cell

Hesperetin is an abundant flavonoid in citrus fruits, and be confirmed to possess a chemo-preventive effect on cancer. Migration and invasion are the main causes of death of cervical cancer patients, in which epithelial-mesenchymal transition (EMT) can directly contribute to malignant phenotypes of tumor cells. The present study aims to investigate the inhibitory effect of hesperetin on EMT-mediated invasion and migration in cervical cancer cells through transforming growth factor-β1 (TGF-β1)/Smads pathway. Cell viability, cell migration and invasion ability, and cell morphology were evaluated and monitored using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assays, Transwell assays and optical microscope, respectively. The change of EMT marker protein E-cadherin and N-cadherin was assessed by immunofluorescence assay, whereas the protein expression of EMT bio-marker and TGF-β1/Smads pathway were detected through western blot analysis. In conclusion, hesperetin can suppress EMT-mediated invasion and migration of cervical cancer cells by inhibiting abnormal activation of TGF-β1/Smads pathway. The study provides an experimental basis for the prevention of the invasion and migration of cervical cancer.

Effect of Hesperidin against Induced Colon Cancer in Rats: Impact of Smad4 and Activin A Signaling Pathway

SCOPE

To evaluate the chemopreventive efficacy of hesperidin (Hsd) in 1,2-dimethylhydrazine (DMH)-induced colorectal cancer (CRC) and demonstrate its role in mothers against decapentaplegic homolog 4(Smad4) and activin A signaling pathways.

METHODS AND RESULTS

A CRC rat model was established by DMH exposure, and the animals were randomly divided into five groups: Control group, Hsd, DMH, DMH + Hsd, and DMH followed by Hsd. The resected colon was subjected to macroscopic, microscopic, molecular, histopathological, and immunohistochemical examination. Activin A, Smad4, malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH), and superoxide dismutase (SOD) levels in tissues were also measured. The DMH group exhibited a significant increase in the gene and protein expression of activin A as well as MDA and NO levels in tissues. There was a significant reduction in the gene and protein expression of Smad4 as well as GSH and SOD levels in tissues. Administration of Hsd significantly upregulated Smad4 and activin A gene expressions in both the DMH + Hsd and DMH followed by Hsd groups. Moreover, Hsd improved the antioxidant status of the former two groups.

CONCLUSION

This study demonstrated the chemopreventive effect of Hsd against CRC by modulating Smad4 and activin A signaling in vivo. Further studies are needed to demonstrate its clinical value and explore its possible role in advanced malignancy.

Hesperetin protects against palmitate-induced cellular toxicity via induction of GRP78 in hepatocytes

Lipotoxicity plays a critical role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Hesperetin, a flavonoid derivative, has anti-oxidant, anti-inflammatory and cytoprotective properties. In the present study, we aim to examine whether hesperetin protects against palmitate-induced lipotoxic cell death and to investigate the underlying mechanisms in hepatocytes. Primary rat hepatocytes and HepG2 cells were pretreated with hesperetin for 30 min and then exposed to palmitate (1.0 mmol/L in primary rat hepatocytes; 0.5 mmol/L in HepG2 cells) in the presence or absence of hesperetin. Necrotic cell death was measured via Sytox green nuclei staining and quantified by LDH release assay. Apoptotic cell death was determined by caspase 3/7 activity and the protein level of cleaved-PARP. The unfolded protein response (UPR) was assessed by measuring the expression of GRP78, sXBP1, ATF4 and CHOP. Results show that hesperetin (50 μmol/L and 100 μmol/L) protected against palmitate-induced cell death and inhibited palmitate-induced endoplasmic reticulum (ER) stress in both primary rat hepatocytes and HepG2 cells. Hesperetin (100 μmol/L) significantly activated sXBP1/GRP78 signaling, whereas a high concentration of hesperetin (200 μmol/L) activated p-eIF2α and caused hepatic cell death. Importantly, GRP78 knockdown via siRNA abolished the protective effects of hesperetin in HepG2 cells. In conclusion, hesperetin protected against palmitate-induced hepatic cell death via activation of the sXBP1/GRP78 signaling pathway, thus inhibiting palmitate-induced ER stress. Moreover, high concentrations of hesperetin induce ER stress and subsequently cause cell death in hepatocytes.

Hesperetin alleviates doxorubicin-induced migration in 4T1 breast cancer cells

Background

Hesperetin (Hst), a citrus flavanone, is widely distributed among citrus fruits, including lemons. Hst has been shown to possess bioactivity as an antioxidant, anti-inflammatory, anti-allergic, hypolipidemic, vasoprotector, and anticancer agent. This study aimed to identify potential combinations of Hst and the chemotherapeutic agent doxorubicin (Dox) as co-chemotherapy agents against 4T1 murine metastatic breast cancer cells.

Results

MTT assay results showed that Hst exhibited cytotoxic effect in 4T1 cells, and its combination with Dox showed a synergistic effect based on the CI value. The combination of Hst and Dox increased G2/M phase cell cycle arrest and apoptosis induction. The combination of Hst and Dox inhibited migration and decreased MMP-9 expression in 4T1 cells.

Conclusion

In conclusion, the results of this study show that Hst has potential as a Dox co-chemotherapy against 4T1 cells by inducing G2/M phase cell cycle arrest and apoptosis. More importantly, Hst reduces Dox-induced migration and decreases MMP-9 expression.

Cytotoxic and Antimetastatic Activity of Hesperetin and Doxorubicin Combination Toward Her2 Expressing Breast Cancer Cells

OBJECTIVE

This study aimed to explore Hesperetin (Hst) potency as a co-chemotherapeutics agent combined with Doxorubicin (Dox), particularly cytotoxic and antimetastasis effects toward MCF-7/HER2 cells.

METHODS

The cytotoxic effects were measured under MTT assay. The flowcytometry analysis was used to examine the cell cycle modulation and apoptosis evidence, while the effect of migration was assayed by scratch wound healing assay. Western blotting and gelatin zymography were carried out to examine the expression level of proteins, HER2, and Rac1.

RESULTS

Under MTT assay, Hst and Dox exhibited to decrease cell viability in a dose-dependent manner with the IC50 value of 377 and 0,8 µM, respectively. The combination of Hst and Dox at the respective doses of 95 and 0,2 µM showed a synergistic effect with the combination index of 0,63. Flow cytometry analysis of Hst-Dox revealed that those compounds caused cell cycle arrest at the G2/M phase and induced apoptosis. Hst also decreased HER2 and Rac1 expression, as shown by western blot. Hst inhibited lamellipodia formation and cell migration, as indicated by microscopic observation and wound healing scratch assay. The antimetastatic activity of Hst was associated with the reduction of Rac1 and MMP9 expression as measured by gelatine zymography assay.

CONCLUSION

These results indicated that the combination of Hst and Dox-induced cell cycle arrest, apoptosis, decreased HER2, Rac1, MMP9 expression, and cell migration. Thus, Hst may have the potential to be developed as a co-chemotherapeutic agent combined with doxorubicin toward HER2 overexpressing breast cancer cells.

Molecular mechanisms of action of hesperidin in cancer: Recent trends and advancements

Hesperidin belongs to flavanones class of flavonoids and is known to possess broad-spectrum applicability to prevent dreadful diseases such as cardiovascular disease, neurodegeneration, and cancer. The reported anticancer effects of hesperidin have been found to be associated with its anti-oxidant and anti-inflammatory activities. Hesperidin interacts with numerous recognized cellular targets and inhibits cancer cell proliferation by inducing apoptosis and cell cycle arrest. In addition, evidence has suggested its promising role in inhibiting tumor cell metastasis, angiogenesis, and chemoresistance. The present mini-review highlights the ongoing development to identify hesperidin targets in cancer. Furthermore, the potential of nano technology-based hesperidin combinations and delivery systems will also be discussed. Overall, this review highlights all the possible molecular targets affected by hesperidin in tumor cells on a single platform.

Impact statement

Experimental findings from numerous studies have demonstrated the anticancer effects of hesperidin (Hesp) to be associated with anti-oxidant and anti-inflammatory activities along with its potential role in inhibiting the tumor cell metastasis and angiogenesis. Additionally, Hesp can also reverse drug resistance of cancer cells, which make it a promising candidate to be used in combination with existing anti-cancer drugs. This review will be helpful for upcoming researchers and scientific community to find out complete capsular package about cancer drug targets of Hesp and its role in modulating various important hallmarks of cancer.

An Array of Bioactive Compounds From Australian Eucalypts and Their Relevance in Pancreatic Cancer Therapeutics

Pancreatic cancer (PC) is one of the most devastating human cancers, and despite the significant advances in the current therapeutic options, the overall survival rate for PC has remained static for the past 50 years. Plant-derived bioactive compounds play a vital role in cancer therapeutics by providing new lead compounds for future drug development. Therefore, the isolation, characterization, and identification of new bioactive compounds for the prevention and treatment of cancer continue to be an important aspect of natural product research. Many in vitro and in vivo studies published in the last few decades have established strong links between the phytochemical profile of eucalypts and anticancer activity. However, only a small number of these reports have attempted to demonstrate a relationship between the biological activity of eucalypt extracts and PC. This review focuses on potential anti-PC effects of an array of bioactive compounds present in various species of eucalypts. It also highlights the necessity for further in vitro and in vivo studies to develop a complete understanding of the potential this group of plants has for the development of potent and specific chemotherapeutic drugs for PC.

Effect of training system and climate conditions on phytochemicals of Passiflora setacea, a wild Passiflora from Brazilian savannah

Passiflora setacea is a Brazilian savannah fruit known as a good source of phytochemicals. The phytochemical composition is influenced by environmental factors and management techniques such as training system. This study aimed to evaluate the influence of training system (espalier or trellis) and environmental factors (temperature, precipitation and sunlight exposure) on antioxidant capacity and bioactive composition of P. setacea pulp. Total phenolic compounds (TP), proantocyanidins (PA), total flavonoids (TF), vitamin C and total antioxidant activity were analyzed. Five flavonoids (orientin, isoorientin, vitexin, isovitexin and hesperetin) were determined by HPLC-DAD, using calibration curves. Training system presented no effects on TP, PA, TF and antioxidant activity, whereas rainy season year 2 increased FRAP values, TF, orientin, isovitexin and hesperetin content, which could be associate to climate stressful condition leading to higher levels of these compounds.

Quantitative single-molecule study of TGF-β/Smad signaling

TGF-β/Smad signaling pathway triggers diverse cellular responses among different cell types and environmental conditions. Quantitative analysis of protein-protein interactions involved in TGF-β/Smad signaling is demanded for understanding the molecular mechanism of this signaling pathway. Live-cell single-molecule microcopy with high spatiotemporal resolution is a new tool to monitor key molecular events in a real-time manner. In this review, we mainly presented the recent work on the quantitative characterization of TGF-β/Smad signaling proteins by single-molecule method, and showed how it enabled us to obtain new insights about this canonical signaling process.

Is Failure of Cocrystallization Actually a Failure? Eutectic Formation in Cocrystal Screening of Hesperetin

Cocrystal screening of hesperetin with certain countermolecules generated highly soluble noncovalent derivatives in the form of eutectics, instead of expected cocrystals. As adhesive forces established by complimentary functional groups on hesperetin and coformers were unable to overcome the stress due to size shape mismatch of component molecules, thus, eutectics were formed. Hesperetin, a polyphenolic antioxidant with potent anticancer and cardioprotective effects, has an underdeveloped role in modern therapeutics on account of its critically low aqueous solubility resulting in stunted bioavailability. The liquid-assisted cogrinding of hesperetin and coformers generated binary-phase eutectics in fixed stoichiometry with theophylline (1:1.5), adenine (2:1), gallic acid (1.5:1), and theobromine (2:1). Primarily characterized by lower melting endotherm in differential scanning calorimetry, the eutectics showed complete melting in hot-stage microscopy. Apart from characteristic V-shaped binary-phase diagram, no discernible changes in the FTIR and powder X-ray diffraction spectra further confirm eutectic formation. The morphological differences were analyzed by SEM measurements. A 2 to 4 times enhanced dissolution profile of the eutectics measured in pH 7.4 aqueous buffer was coupled with the in vitro (1,1-diphenyl-2-picryl hydroxyl free radical antioxidant assay and RBC antihemolytic assay) studies to present a complete preliminary data on the improved bioavailability of hesperetin eutectics.

Evaluating the Effect of Lidocaine on the Interactions of C-reactive Protein with Its Aptamer and Antibody by Dynamic Force Spectroscopy

Effects of medicine on the biomolecular interaction have been given extensive attention in biochemistry and biomedicine because of the complexity of the environment in vivo and the increasing opportunity of exposure to medicine. Herein, the effect of lidocaine on the interactions of C-reactive protein (CRP) with its aptamer and antibody under different temperature was investigated through dynamic force spectroscopy (DFS). The results revealed that lidocaine could reduce the binding probabilities and binding affinities of the CRP-aptamer and the CRP-antibody. An interesting discovery was that lidocaine had differential influences on the dynamic force spectra of the CRP-aptamer and the CRP-antibody. The energy landscape of the CRP-aptamer turned from two activation barriers to one after the treatment of lidocaine, while the one activation barrier in energy landscape of the CRP-antibody almost remained unchanged. In addition, similar results were obtained for 25 and 37 °C. In accordance with the result of molecular docking, the reduction of binding probabilities might be due to the binding of lidocaine on CRP. Additionally, the alteration of the dissociation pathway of the CRP-aptamer and the change of binding affinities might be caused by the conformational change of CRP, which was verified through synchronous fluorescence spectroscopy. Furthermore, differential effects of lidocaine on the interactions of CRP-aptamer and CRP-antibody might be attributed to the different dissociation processes and binding sites of the CRP-aptamer and the CRP-antibody and different structures of the aptamer and the antibody. This work indicated that DFS provided information for further research and comprehensive applications of biomolecular interaction, especially in the design of biosensors in complex systems.

Hesperetin Liposomes for Cancer Therapy

Hesperetin is a compound from citrus fruit that has previously been found to exert anticancer activity through a variety of mechanisms. However, the application of hesperetin to cancer therapy has been hampered by its hydrophobicity, necessitating the use of toxic solubilizing agents. Here, we have developed the first liposome-based delivery system for hesperetin. Liposomes were fabricated using the thin-layer evaporation technique and physical and pharmacological parameters were measured. The liposomes remained stable for prolonged periods of time in serum and under storage conditions, and displayed anticancer efficacy in both H441 lung cancer cells and MDA-MB-231 breast cancer cells. Furthermore, the anticancer activity was not impaired in cells expressing the multidrug resistance protein 1 (MDR-1). In conclusion, the encapsulation of hesperetin in liposomes does not interfere with therapeutic efficacy and provides a biocompatible alternative to toxic solubilizing agents, thereby enabling future clinical use of this compound for cancer therapy.

Hesperetin Induces the Apoptosis of Gastric Cancer Cells via Activating Mitochondrial Pathway by Increasing Reactive Oxygen Species

BACKGROUND

Hesperetin, has been shown to exert biological activities on various types of human cancers. However, few related studies on gastric cancer are available.

AIM

In this study, we sought to investigate the effect of hesperetin on gastric cancer and clarify its specific mechanism.

MATERIALS AND METHODS

Cell Counting Kit-8, 2',7'-dichlorofluorescin diacetate, JC-1, Hoechst 33258 staining, and western bolt were used to detect cell viability, levels of intracellular reactive oxygen species (ROS), changes in mitochondrial membrane potential (△ψ m), cell apoptosis, and expressions of mitochondrial pathway proteins, respectively. Meanwhile, xenograft tumor models in nude mice were made to evaluate the effect of hesperetin on gastric cancer in vivo.

RESULTS

Compared with the control group, the proliferation of gastric cancer cells in hesperetin groups was significantly inhibited (P < 0.05), and dose- and time-dependent effects were observed. Pretreatment with H2O2 (1 mM) or N-acetyl-L-cysteine (5 mM) enhanced or attenuated the hesperetin-induced inhibition of cell viability (P < 0.05). Percentages of apoptotic cells, levels of intracellular ROS, and △ψ m varied with the dose and treatment time of hesperetin (P < 0.05), and hesperetin caused an increase in the levels of AIF, Apaf-1, Cyt C, caspase-3, caspase-9, and Bax and a decrease in Bcl-2 levels (P < 0.05). Meanwhile, hesperetin significantly inhibited the growth of xenograft tumors (P < 0.05).

CONCLUSION

Our study suggests that hesperetin could inhibit the proliferation and induce the apoptosis of gastric cancer cells via activating the mitochondrial pathway by increasing the ROS.

Epithelial-mesenchymal transition: An emerging target in tissue fibrosis

Epithelial-mesenchymal transition (EMT) is involved in a variety of tissue fibroses. Fibroblasts/myofibroblasts derived from epithelial cells contribute to the excessive accumulation of fibrous connective tissue in damaged tissue, which can lead to permanent scarring or organ malfunction. Therefore, EMT-related fibrosis cannot be neglected. This review highlights the findings that demonstrate the EMT to be a direct contributor to the fibroblast/myofibroblast population in the development of tissue fibrosis and helps to elucidate EMT-related anti-fibrotic strategies, which may enable the development of therapeutic interventions to suppress EMT and potentially reverse organ fibrosis.

Hesperetin induces the apoptosis of hepatocellular carcinoma cells via mitochondrial pathway mediated by the increased intracellular reactive oxygen species, ATP and calcium

Hesperetin, a flavonoid from citrus fruits, has been proved to possess biological activity on various types of human cancers. However, few related studies on hepatocellular carcinoma are available. In this study, we aimed to investigate the effect of hesperetin on hepatocellular carcinoma cells in vitro and in vivo and clarify its potentially specific mechanism. Compared with the control group, the proliferations of hepatocellular carcinoma cells in hesperetin groups were significantly inhibited (P < 0.05), and a dose- and time-dependent inhibition of cell viability was observed. When pretreated with H2O2 (1 mM) or N-acetyl-L-cysteine (5 mM), the inhibition of cell viability by hesperetin was enhanced or reduced, respectively (P < 0.05). Similarly, the levels of intracellular ROS, ATP and Ca(2+) changed in different groups (P < 0.05). The results of Hoechst 33258 staining showed that the percentages of apoptotic cells in hesperetin groups are remarkably higher than that in control group (P < 0.05). And the results of Western blot showed that hesperetin caused an increase in the levels of cytosolic AIF, cytosolic Apaf-1, cytosolic Cyt C, caspase-3, caspase-9 and Bax and a decrease in that of Bcl-2, mitochondrial AIF, mitochondrial Apaf-1 and mitochondrial Cyt C (P < 0.05). Meanwhile, hesperetin significantly inhibited the growth of xenograft tumors. Our study suggests that hesperetin could inhibit the proliferation and induce the apoptosis of hepatocellular carcinoma via triggering the activation of the mitochondrial pathway by increasing the levels of intracellular ROS, ATP and Ca(2+).

Safety of Nanoparticles in Medicine

Nanomedicine involves the use of nanoparticles for therapeutic and diagnostic purposes. During the past two decades, a growing number of nanomedicines have received regulatory approval and many more show promise for future clinical translation. In this context, it is important to evaluate the safety of nanoparticles in order to achieve biocompatibility and desired activity. However, it is unwarranted to make generalized statements regarding the safety of nanoparticles, since the field of nanomedicine comprises a multitude of different manufactured nanoparticles made from various materials. Indeed, several nanotherapeutics that are currently approved, such as Doxil and Abraxane, exhibit fewer side effects than their small molecule counterparts, while other nanoparticles (e.g. metallic and carbon-based particles) tend to display toxicity. However, the hazardous nature of certain nanomedicines could be exploited for the ablation of diseased tissue, if selective targeting can be achieved. This review discusses the mechanisms for molecular, cellular, organ, and immune system toxicity, which can be observed with a subset of nanoparticles. Strategies for improving the safety of nanoparticles by surface modification and pretreatment with immunomodulators are also discussed. Additionally, important considerations for nanoparticle safety assessment are reviewed. In regards to clinical application, stricter regulations for the approval of nanomedicines might not be required. Rather, safety evaluation assays should be adjusted to be more appropriate for engineered nanoparticles.

Role of the prostaglandin E2/E-prostanoid 2 receptor signalling pathway in TGFβ-induced mice mesangial cell damage

The prostaglandin E2 receptor, EP2 (E-prostanoid 2), plays an important role in mice glomerular MCs (mesangial cells) damage induced by TGFβ1 (transforming growth factor-β1); however, the molecular mechanisms for this remain unknown. The present study examined the role of the EP2 signalling pathway in TGFβ1-induced MCs proliferation, ECM (extracellular matrix) accumulation and expression of PGES (prostaglandin E₂ synthase). We generated primary mice MCs. Results showed MCs proliferation promoted by TGFβ1 were increased; however, the production of cAMP and PGE₂ (prostaglandin E₂) was decreased. EP2 deficiency in these MCs augmented FN (fibronectin), Col I (collagen type I), COX2 (cyclooxygenase-2), mPGES-1 (membrane-associated prostaglandin E1), CTGF (connective tissue growth factor) and CyclinD1 expression stimulated by TGFβ1. Silencing of EP2 also strengthened TGFβ1-induced p38MAPK (mitogen-activated protein kinase), ERK1/2 (extracellular-signal-regulated kinase 1/2) and CREB1 (cAMP responsive element-binding protein 1) phosphorylation. In contrast, Adenovirus-mediated EP2 overexpression reversed the effects of EP2-siRNA (small interfering RNA). Collectively, the investigation indicates that EP2 may block p38MAPK, ERK1/2 and CREB1 phosphorylation via activation of cAMP production and stimulation of PGE₂ through EP2 receptors which prevent TGFβ1-induced MCs damage. Our findings also suggest that pharmacological targeting of EP2 receptors may provide new inroads to antagonize the damage induced by TGFβ1.

RETRACTED: Quercetin suppresses insulin receptor signaling through inhibition of the insulin ligand-receptor binding and therefore impairs cancer cell proliferation

Although the flavonoid quercetin is known to inhibit activation of insulin receptor signaling, the inhibitory mechanism is largely unknown. In this study, we demonstrate that quercetin suppresses insulin induced dimerization of the insulin receptor (IR) through interfering with ligand-receptor interactions, which reduces the phosphorylation of IR and Akt. This inhibitory effect further inhibits insulin stimulated glucose uptake due to decreased cell membrane translocation of glucose transporter 4 (GLUT4), resulting in impaired cancer cell proliferation. The effect of quercetin in inhibiting tumor growth was also evident in an in vivo model, indicating a potential future application for quercetin in the treatment of cancers.

Preparation and characterization of biocompatible and thermoresponsive micelles based on poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) grafted on polysuccinimide for drug delivery

Biocompatible and temperature-sensitive amphiphilic polymeric micelles comprised of poly(succinimide)- g-poly( N-isopropylacrylamide- co-N, N-dimethylacrylamide) (PSI- g-poly(NIPAAm- co-DMAAm)) were synthesized to use as new drug carriers. The PSI- co-poly(PNIPAAm- co-DMAAm) polymers were prepared by nucleophilic opening of poly(succinimide) using amino-terminated poly(NIPAAm- co-DMAAm). The lower critical solution temperature of the copolymer was 40.6℃ higher than normal human body temperature. The blank polymeric micelles were observed to have a regular spherical shape, and the particle sizes were approximately 85 nm. This copolymer exhibited no significant cytotoxicity and hemolysis indicated that the micelles had good biocompatibility. In addition, these polymeric micelles encapsulated the anti-inflammatory drug, hesperetin, in the inner core with a drug loading content of approximately 20%. The release profiles of hesperetin showed a significant temperature-sensitive switching behavior. The hesperetin release response was dramatically lower at a temperature below the lower critical solution temperature as compared with a temperature above the lower critical solution temperature. The lipopolysaccharide-induced nitric oxide production inhibition experiments demonstrated that hesperetin-encapsulated micelles showed a significant reduction. In this study, the biocompatible temperature-sensitive micelles based on PSI- g-poly(NIPAAm- co-DMAAm) have great potential to act as a suitable carrier for drug delivery.

Fruit-derived phenolic compounds and pancreatic cancer: perspectives from Australian native fruits

ETHNOPHARMACOLOGICAL RELEVANCE

Pancreatic cancer is a devastating cancer that presents late, is rapidly progressive and has current therapeutics with only limited efficacy. Bioactive compounds are ubiquitously present in fruits and numerous studies in vitro are addressing the activity of these compounds against pancreatic cancer, thus studies of specific bioactive compounds could lead to new anti-pancreatic cancer strategies. Australian native fruits have been used as foods and medicines by Australian Aboriginals for thousands of years, and preliminary studies have found these fruits to contain rich and diversified bioactive components with high antioxidant activity. Thus, Australian native fruits may possess key components for preventing or delaying the onset of tumorigenesis, or for the treatment of existing cancers, including pancreatic cancer.

MATERIALS AND METHODS

Numerous databases including PubMed, SciFinder, Web of Knowledge, Scopus, and Sciencedirect were analysed for correlations between bioactive components from fruits and pancreatic cancer, as well as studies concerning Australian native fruits.

RESULTS

In this review, we comprehensively highlight the proposed mechanisms of action of fruit bioactives as anti-cancer agents, update the potential anti-pancreatic cancer activity of various major classes of bioactive compounds derived from fruits, and discuss the existence of bioactive compounds identified from a selection Australian native fruits for future studies.

CONCLUSION

Bioactive compounds derived from fruits possess the potential for the discovery of new anti-pancreatic cancer strategies. Further, Australian native fruits are rich in polyphenols including some flora that contain unique phenolic compounds, thereby warranting further investigations into their anti-cancer properties.

Hesperetin activates the Notch1 signaling cascade, causes apoptosis, and induces cellular differentiation in anaplastic thyroid cancer

BACKGROUND

Anaplastic thyroid cancer (ATC) is characterized by very aggressive growth with undifferentiated features. Recently, it has been reported that the Notch1 signaling pathway, which affects thyrocyte proliferation and differentiation, is inactivated in ATC. However, it remains largely unknown whether using Notch1 activating compounds can be an effective therapeutic strategy in ATC. Therefore, in this study, we aimed to evaluate the drug effects of a potential Notch activator hesperetin on ATC cell.

METHODS

A unique ATC cell line HTh7 was used to evaluate the drug effects of hesperetin. The Notch1 activating function and cell proliferation were evaluated. The mechanism of growth regulation was investigated by the detection of apoptotic markers. The expression levels of thyrocyte-specific genes were quantified for ATC redifferentiation.

RESULTS

Upregulated expression of Notch1 and its downstream effectors hairy and enhancer of split 1 (Hes1) and Hes1 related with YRPW motif was observed in hesperetin-treated ATC cells. The enhanced luciferase signal also confirmed the functional activity of hesperetin-induced Notch1 signaling. Hesperetin led to a time- and dose-dependent decrease in ATC cell proliferation. The cell-growth inhibition was mainly caused by apoptosis as evidenced by increased levels of cleaved poly ADP ribose polymerase and cleaved caspase-3 as well as decreased survivin. Additionally, hesperetin induced the expression levels of thyrocyte-specific genes including thyroid transcription factor 1 (TTF1), TTF2, paired box gene 8, thyroid stimulating hormone receptor, and sodium/iodide symporter.

CONCLUSIONS

Hesperetin activates the Notch1 signaling cascade and suppresses ATC cell proliferation mainly via apoptosis. Hesperetin also induces cell redifferentiation of ATC, which could be useful clinically.

Anticancer activity of liposomal bergamot essential oil (BEO) on human neuroblastoma cells

Citrus extracts, particularly bergamot essential oil (BEO) and its fractions, have been found to exhibit anticancer efficacy. However, the poor water solubility, low stability and limited bioavailability have prevented the use of BEO in cancer therapy. To overcome such drawbacks, we formulated BEO liposomes that improved the water solubility of the phytocomponents and increased their anticancer activity in vitro against human SH-SY5Y neuroblastoma cells. The results warrant further investigation of BEO liposomes for in vivo applications.

Binding of pro-migratory serum factors to electrospun PLLA nano-fibers

Architecture of the poly(l-lactic acid) (PLLA) scaffolds is known to affect protein affinity and binding strength. Here, we demonstrate that nanofibrous electrospun PLLA scaffolds reversibly absorb the pro-migratory serum factors that stimulate migration of vascular smooth muscle via an NFkB-dependent mechanism. Further, we demonstrate that mesenchymal stem cells seeded on the PLLA scaffolds do not enhance muscle migration but may maintain the ability of induced cells to migrate in an NFkB-independent manner. These findings further support the promising application of PLLA scaffolds for therapeutic angiogenesis and vascular graft engineering.

Predicting the Drug Safety for Traditional Chinese Medicine through a Comparative Analysis of Withdrawn Drugs Using Pharmacological Network

As the major issue to limit the use of drugs, drug safety leads to the attrition or failure in clinical trials of drugs. Therefore, it would be more efficient to minimize therapeutic risks if it could be predicted before large-scale clinical trials. Here, we integrated a network topology analysis with cheminformatics measurements on drug information from the DrugBank database to detect the discrepancies between approved drugs and withdrawn drugs and give drug safety indications. Thus, 47 approved drugs were unfolded with higher similarity measurements to withdrawn ones by the same target and confirmed to be already withdrawn or discontinued in certain countries or regions in subsequent investigations. Accordingly, with the 2D chemical fingerprint similarity calculation as a medium, the method was applied to predict pharmacovigilance for natural products from an in-house traditional Chinese medicine (TCM) database. Among them, Silibinin was highlighted for the high similarity to the withdrawn drug Plicamycin although it was regarded as a promising drug candidate with a lower toxicity in existing reports. In summary, the network approach integrated with cheminformatics could provide drug safety indications effectively, especially for compounds with unknown targets or mechanisms like natural products. It would be helpful for drug safety surveillance in all phases of drug development.